<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script src="https://unpkg.com/vue@next"></script>
    <div id="app">
        <todo-item></todo-item>
    </div>
    
    <script>
        const {createApp, defineAsyncComponent} = Vue;

        const vueOpt = {
            data(){
                return {

                }
            }
        }

        const app = createApp(vueOpt);

        const AsyncCom = defineAsyncComponent(()=>{
            return new Promise((resolve, reject)=>{
                resolve({
                    template: `<div>I am async component</div>`
                })
            });
        });

        app.component('todo-item', AsyncCom);
        app.mount('#app');
        
    </script>
</body>
</html>